Antistall device



Feb. 20, 1940. J, SCHWEISS 4 2,190,738

ANTISTALL DEVICE Filed Sept. 19, 1938 Egg@ y .fm/enfoca d-Ose/o c/we/SSPatented Feb. 20, 1940 UNITED STATES PATENT OFFICE AN'rIs'r-ALL DEVICEApplication September 19, 1938, Serial No. 230,716

3 Claims.

'I'his invention relates to carburetors for in-v ternal combustionengines and consists particularly in a novel antistalling devicetherefor.

Devices have been suggested which utilize 5 intake manifoldy suction toslightly open the carburetor throttle valve whenever the suction in theengine intake system drops excessively. These devices hold the throttlevalve open when there is no suction in the intake system, or in i lother words, when the engine is inoperative and thus cannot be'used incarburetors having antipercolating mechanism, as described, lforinstance, in Moseley Patent No. 2,013,787. 'I'his `mechanism requiresfull closing of the throttle l valve when the engine is inoperative inorder to open a vent for relieving vapor pressure formed at the base ofthe main nozzle and prevent the gasoline from spilling into the intakemanifold.

It is an object of the present invention to provide an antistall devicewhich may be utilized with a carburetor embodying antipercolating.

mechanism as described in the Moseley patent.

Another object is to provide an antistall device which is constructedand arranged to insure slight opening of the throttle valve when thesuction in the engine intake system drops sui'- ciently to indicate thatthe engine will stall if the throttle valve is permitted to fully close,but which permits full closing of the throttle valve at all other times.

These objects and other more detailed objects hereafter appearing areattained substantially by the structures illustrated in the accompanyingdrawing in which:

Fig. 1 is a side view of a portion of an internal combustion engineintake system including the carburetor and apart of the intakefmanifold,with the invention applied thereto.

Fig. 2 is a detail section taken substantially on line 2-2 of Fig. 3.

Fig. 3 is a detail side view and section taken substantially on line 3-3of Fig. 1.

Fig. 4 is a side view and section illustrating a modification.

Fig. 5 is an enlarged diagrammatic view illus,- trating a part of thestructure in Fig. 4.

Fig. 6 is a view showing a part of the structure inFig. 2, but in adifferent position.

Fig. 1 illustrates a downdraft carburetor in- 50 cluding a barrelportion I, flanged-at its lower end as at 2 and attached by means ofbolts 3 to the intake manifold 4, the usual "hot spot 5 being provided.The usual constant level chamber 6 is located adjacent barrel I.Pivotally 5| mounted on shaft 1 near the lower portion of barrel I, is abutterfly-type throttle valve 8. Shaft 1 projects beyond both sides ofthe barrel and at one'end carries an arm 9 for connection to the usualaccelerating pump (not shown) by means of a link 9a and lever 9b. Alever I0 rigid 5 with the other end of shaft 1 has two pairs ofVoutstanding threaded lugs II and I2 mounting stop screws I3 and I4.Lever I0 is perforated at one end as at I5, for attachment to the usualmanual control mechanism connected to the ac- 10 celerator pedal.

A bracket I 6 is mounted between the carburetor flange and manifold andat its outer end carries a suction device generally indicated at I1.Device |1 includes a diaphragm I8 normally urged 15 to the right byl acoiled spring I9 (see Fig. 4). A tube 20 connects the device with theintake manifold suction. A guide tube 2l extends horizontally from thesuction device and slidably receives a rod 22 secured to the vdiaphragmand 20 having at its outer extremity annular ridges 23, 24 and 25 withrecesses 26 and 21 therebetween. A small hole or recess 28 in the upperwall of tube 2I near the outer end thereof receives a loose ball plunger29 whch is in position to be 25 engaged by screw I4 on lever IU.

In operation, suction device I1 is constructed to insure the maintenanceof diaphragm I8 in its left hand or inward position whenever normaloperative suction exists in the intake manifold, 3o

this including the lowest suction which prevails when the throttle valveis substantially closed and with the engine continuing in operation.Spring I9 is calibrated to move diaphragm I8 and rod 22 to the rightonly when the intake suc- 35 tion approaches zero so as to indicate thatthe engine is about to stall unless the throttle valve is opened. In such case middle ridge 24 on rod 22 is moved under ball 29, as shown inFig. 6, raising the same into the path of screw I4 so as 40 to preventfull closing of the throttle valve or to open the valve slightly if itis already closed. When the speed of the engine again picks up,diaphragm' I8 is drawn to the left permitting ball 29 to drop intorecess 21. When the engine stops 45 operating and there is no suction inthe intake system, spring |19 forces rod 22 fully to the rightpermitting ball 29 to drop into recess 26, as in Fig. 2. This permitsfull closing of the throttle valve and, consequently, opening of theantipercolator vent, as described in the above mentioned Moseley patent.Screw I4 is adjusted so as to just clear ball 29 when the latter is ineither of the recesses 26 or 21. Screw I3 cooperates with a stop 30 onthe outside of barrel I to limit 55 the closing movement of the throttlevalve to. its normal idling position.

In Figs. 4 and 5 is shown a modiiication utilizing a suction device l1as in the previous form. A lever 35 is pivoted at 36 to carburetorbarrel I and a bell. crank lever 31 is pivotally connected to the lowerextremity thereof, as at 38. Lever 31 has a curved slot 39 in the lowerportion theref of slidably receiving apin 40 projecting from lever Iliaon throttle shaft 1. Diaphragm actuated rod 22 is pinned to the end oflever 31 opposite slot 39.

Whenever normal operating suction exists in ment of the toggle leversmovesthe upper edge of slot 39 slightly downwardly so as to: engage pin4.0 and prevent full closing of the throttle valve, or open the valve.When there is no suction in the intake system, toggle levers 3.5 and 31vwill be moved to a disaligned position opposite the solid line positionin Fig. 5, again permitting full closing of the throttle valve.

Fig. 5 indicates diagrammatically the three positions of toggle levers35 and 31 which permit free opening movement of the throttle valve at ldrops to a point to indicate that the engine is all times and alsopermit full closing of the valve except when the suction in the intakesystem about to stall.

The novel antistall device may be used with substantially any type ofcarburetor. and, although', an important advantage of the device isobtained when it is used with an anti-percolating device as disclosed inthe above-mentioned Moseley patent, the device has other advantages andmay be used where no anti-percolator is provided. The specic form ofsuction responsive device shown is not essential. The structure shownmay be modied in the above and other respects as will occur to thoseskilled in the art However, in case the intake suction drops conduit,aguide projecting from said device havand the exclusive use of all suchmodications as come within the scope of the appended claims iscontemplated.

I claim:

l. In combination with internal combustion en- 5 gine intakeconduit'including a carburetor having a throttle valve and on operatingarm therefor,'a device responsive to suction in said conduit, a leverpivoted adjacent said mechanism, a second lever pivotally connected tosaid rst lever and having a slot, said arm having an element movable insaid slot and said levers forming a toggle. and a rod operated by saiddevice and connected to one of said levers intermediate Ithe ends of thetoggle so as to disalign said levers when there is normaloperatinggsuction and when there is no suction in said mechanism and tosubstantially valign said levers when the intake pressure apw proachesatmospheric, said throttle arm element being freely movable in said slotto permit full opening andclosing of said throttle valve when saidlevers are disaligned but cooperating with an end of said sloty whensaid levers are aligned to insure at least partial openingof saidthrottle valve.

2. AIn combination with an internal combustion engine intake conduitincluding a carburetor having a throttle valve and operating mechanismtherefor, a device responsive to suction in said ing a recess adjacentsaid mechanism, a plunger in said recess, and a rod connected to saiddevice and vmovable thereby along said guide, 'said rod having a raisedportion for engaging said plunger when the intake pressure approachesatmospheric `to move the same into the path of said mechanismto insureat least partial opening of said throttle valve and said rod havingrecessed structure adjacent said raised portion to permit full closingof'said throttle when the intake suction fails.

3. The combination of elements specified in claim 2 in which saidrecessed structure is constructed and arranged to permit full closing ofsaid throttle valve Vwhen normal operating suc- 4 tions exist in saidintake conduit.v

JOSEPH SCHWEISS.

